public ActionResult Conversion(int[] EG_IDArr, int[] CountArr, int PointSum, int MC_ID)
        {
            using (TransactionScope ts = new TransactionScope())
            {
                MemCard mc = db.MemCards.Find(MC_ID);
                ExchangLog el = new ExchangLog();
                el.S_ID = 1;//默认为自己店铺ID
                el.U_ID = 1;//默认为当前用户ID
                el.MC_ID = mc.MC_ID;
                el.MC_Name = mc.MC_Name;
                el.MC_CardID = mc.MC_CardID;
                for (int i = 0; i < EG_IDArr.Length; i++)
                {
                    //修改 礼品(ExchangGifts)(已兑换的数量    EG_ExchangNum)
                    ExchangGift eg = db.ExchangGifts.Find(EG_IDArr[i]);
                    eg.EG_ExchangNum += CountArr[i];
                    db.Entry(eg).State = EntityState.Modified;
                    db.SaveChanges();
                    //添加 兑换记录(ExchangLogs)
                    el.EG_ID = eg.EG_ID;
                    el.EG_GiftCode = eg.EG_GiftCode;
                    el.EG_GiftName = eg.EG_GiftName;
                    el.EL_Number = CountArr[i];
                    el.EL_Point = eg.EG_Point * CountArr[i];
                    el.EL_CreateTime = DateTime.Now;
                    db.ExchangLogs.Add(el);
                    db.SaveChanges();
                    //return Content("<script>alert('礼品兑换成功！');history.go(-1);</script>");
                }
                //修改 会员(MemCards)（当前积分    MC_Point）
                mc.MC_Point -= PointSum;
                db.Entry(mc).State = EntityState.Modified;
                db.SaveChanges();
                ts.Complete();
                return Content("礼品兑换成功");
            }
        }